package com.app.adapter.recycler;

import android.content.Context;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;

/**
 * 作者：lblbh on 2017/12/11 19:34
 * 邮箱：lanbuhan@163.com
 * 功能：TODO
 */

public class SyLinearLayoutManager extends LinearLayoutManager{
        private static final String TAG = SyLinearLayoutManager.class.getSimpleName();

        public SyLinearLayoutManager(Context context) {
            super(context);
        }

        public SyLinearLayoutManager(Context context, int orientation, boolean reverseLayout) {
            super(context, orientation, reverseLayout);
        }

        private int[] mMeasuredDimension = new int[2];

        @Override
        public void onMeasure(RecyclerView.Recycler recycler, RecyclerView.State state,
                              int widthSpec, int heightSpec) {

            final int widthMode = View.MeasureSpec.getMode(widthSpec);
            final int heightMode = View.MeasureSpec.getMode(heightSpec);
            final int widthSize = View.MeasureSpec.getSize(widthSpec);
            final int heightSize = View.MeasureSpec.getSize(heightSpec);


            int width = 0;
            int height = 0;
            for (int i = 0; i < getItemCount(); i++) {
                measureScrapChild(recycler, i,
                        View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                        View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                        mMeasuredDimension);

                if (getOrientation() == HORIZONTAL) {
                    width = width + mMeasuredDimension[0];
                    if (i == 0) {
                        height = mMeasuredDimension[1];
                    }
                } else {
                    height = height + mMeasuredDimension[1];
                    if (i == 0) {
                        width = mMeasuredDimension[0];
                    }
                }
            }
            switch (widthMode) {
                case View.MeasureSpec.EXACTLY:
                    width = widthSize;
                case View.MeasureSpec.AT_MOST:
                case View.MeasureSpec.UNSPECIFIED:
            }

            switch (heightMode) {
                case View.MeasureSpec.EXACTLY:
                    height = heightSize;
                case View.MeasureSpec.AT_MOST:
                case View.MeasureSpec.UNSPECIFIED:
            }

            setMeasuredDimension(width, height);
        }

        private void measureScrapChild(RecyclerView.Recycler recycler, int position, int widthSpec,
                                       int heightSpec, int[] measuredDimension) {
            try {
                View view = recycler.getViewForPosition(0);//fix 动态添加时报IndexOutOfBoundsException

                if (view != null) {
                    RecyclerView.LayoutParams p = (RecyclerView.LayoutParams) view.getLayoutParams();

                    int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec,
                            getPaddingLeft() + getPaddingRight(), p.width);

                    int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec,
                            getPaddingTop() + getPaddingBottom(), p.height);

                    view.measure(childWidthSpec, childHeightSpec);
                    measuredDimension[0] = view.getMeasuredWidth() + p.leftMargin + p.rightMargin;
                    measuredDimension[1] = view.getMeasuredHeight() + p.bottomMargin + p.topMargin;
                    recycler.recycleView(view);
                }
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
            }
        }
}